A backlight module is one of key components in a liquid crystal display panel. In general, the backlight module comprises a light source, a backplane, a module frame disposed on the backplane and surrounding the periphery of the backplane, as well as a reflecting sheet, a light guide plate, an optical diaphragm, etc. disposed on the backplane, and on an inner side of the module frame. The inner side of the module frame of the backlight module may be disposed with a liquid crystal cell composed of an array substrate, an opposed substrate, and a liquid crystal layer sandwiched between the array substrate and the opposed substrate. Thus, the backlight module can provide backlight with sufficient brightness and uniform distribution for the liquid crystal cell.
In a production process of the array substrate, after a thin film transistor (TFT) array is fabricated, a test line will be formed on the array substrate, for detecting various types of incidence of defects of the thin film transistor array. Since the test line is specifically used for testing the thin film transistor array, in a subsequent cutting process, a portion of the test line designed outside a cutting line will be cut off, and a portion within the cutting line will be reserved. Thus, a fracture of the cut test line will be formed at an edge of the array substrate.
Since the fracture of the cut test line is in an exposed state, it is impossible to completely seal and insulate, static electricity may enter into an internal circuit of the array substrate from the cut test line, resulting in occurrence of electro-static discharge (ESD), which destroys the internal circuit of the array substrate, and further leads to abnormal display.